1. 608zz bearing: single row bearing, used to bear and axial loads. 2. There are protective covers on both sides to prevent the entry of lubricants and contaminants. 3. Light weight, easy to install and carry 4. Suitable for skateboards, inline skates, and other skating applications. 5. The bearing is lubricated with oil to . Inner diameter is 8mm and outer diameter is 22mm, 7mm in thickness, it is standard 608 bearing size. The bearing is made of chrome steel for durability and resistance to deformity under heavy loads. Shields on both sides ,they protect well against exposure to dust, dirt, and moisture, easy to disassemble and clean. colour:Silver Material:Carbon steel size:22x8x7mm Package Contents: 16 x 608zz Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.